Early tumor growth between initial resection and radiotherapy of glioblastoma: incidence and impact on clinical outcomes

Abstract

Early tumor growth, or increased contrast-enhancing tumor not related to evolving post-surgical injury, in the interval between surgical resection and initiation of radiotherapy has implications for treatment planning and clinical outcomes. In this study we evaluated the incidence of early tumor growth, correlated tumor growth with survival outcome measures, and assessed predictors of early tumor growth in glioblastoma. We reviewed the records of patients with newly-diagnosed glioblastoma who underwent surgical resection and chemoradiotherapy at our institution. Patients with preoperative, immediate postoperative, and preradiotherapy MRI were included. Conventional MRI and DWI features were assessed. The correlation between early tumor growth and extent of resection with survival was assessed with Kaplan–Meier analysis. Logistic regression was carried out to evaluate predictors of early tumor growth. Of 140 included patients, sixty-seven cases (48%) had new or increased contrast enhancement attributed to early tumor growth. Median progression free survival (PFS) and overall survival (OS) were shorter in patients with early tumor growth compared to those without early tumor growth (p < 0.001 for both). Additionally, PFS and OS were longer in patients who underwent gross total resection of enhancing tumor (p = 0.016 and <0.001, respectively). Of the evaluated predictors of early growth, subtotal resection was most likely to result in early growth (p < 0.001). Imaging evidence of early tumor growth is often observed at preradiotherapy MRI and is associated with shorter survival. Gross total resection of contrast enhancing tumor decreases likelihood of early tumor growth.

Pre-Radiotherapy Progression after Surgery of Newly Diagnosed Glioblastoma: Corroboration of New Prognostic Variable

“…About half of the patients (46/90; 51%) progressed between surgery and initiation of adjuvant RT, regardless of waiting time to RT initiation. High incidence of REP and reports of overall survival are in accordance with other retrospective published studies [10][11][12]. The only one clinical negative predictive factor for the development of REP in our cohort was non-radical surgery, confirming the overall prognostic value of surgical radicality in glioblastoma [1].…”

“…REP diagnosis is based on a comparison of early postoperative MRI findings (up to 72 h postoperatively) and planning pre-RT MRI. Only a few studies retrospectively evaluated REP and indicated almost up to 50% risk of development of REP, regardless of the waiting time until the start of radiotherapy (RT) [10][11][12]. Clearly, these patients biased previous clinical trials, where no routine pre-RT MRI examination was performed.…”

Interim Tumor Progression and Volumetric Changes of Surgical Cavities during the Surgery-to-Radiotherapy Interval in Anaplastic Gliomas: Implications for Additional Pre-radiotherapy Magnetic Resonance Imaging

“…Recently, Wee et al [9] have reported a significant incidence of 19.3% of IPD using two separate MRIs taken during the SRI in glioblastoma patients, and have recommended the routine use of additional pre-RT MRIs for disease evaluation and accurate RT-target delineation. The rapid growth of glioblastoma in a short-term interval has been confirmed by other investigators as well [10][11][12][13][14]. However, no study has investigated on the growth dynamics of AGs, particularly, the incidence of IPD during SRI.…”

“…The natural growth of glioblastoma evaluated by MRIs during the SRI has been studied by several investigators [9][10][11][12]. Pirzkall et al [11] reported that increase in volume or new onset of contrast-enhancement occurred in 53% of glioblastoma patients during the SRI.…”

“…Pirzkall et al [11] reported that increase in volume or new onset of contrast-enhancement occurred in 53% of glioblastoma patients during the SRI. Recently, Villanueva-Meyer et al [12] have also reported that nearly half of glioblastoma patients show new or increased contrast-enhance- Values are presented as number (%). IPD, interim disease progression; T1CE, contrast-enhancement of T1-weighted image.…”