Knut Håkon Hole

Radiological and clinical assessment of long-term brain tumour survivors after radiotherapy

BACKGROUND AND PURPOSE Late adverse effects of therapeutic brain radiotherapy (RT) may develop after long latency periods and our objective was to assess long-term brain tumour survivors following RT to large partial brain volumes. MATERIALS AND METHODS Assessment of MRI, SOMA/LENT score, quality of life and neuroendocrine function was performed in 33 adult brain tumour patients 6-25 years following RT. Fraction dose was 1.8 Gy to a median total dose of 54 Gy (range: 45.0-59.4 Gy). Ten patients had been given two opposing portals including one whole hemisphere, while 23 patients had in addition received an ipsilateral field. In 25 patients the hypothalamic and pituitary area had been included in the RT field. Results were compared within the study group and towards the general population matched for age and gender. RESULTS All patients had white matter changes with increased signal intensity on T2 and FLAIR images. Discrete lesions (grade 1), beginning confluence of lesions (grade 2), and large confluent areas (grade 3) were present in 8, 8 and 17 patients, respectively. Patients treated with intra-arterial chemotherapy and patients at higher age at follow-up had significantly more grade 3 changes. Atrophy, lacunar lesions and contrast enhancement was found in 17, 18 and 23 patients, respectively. Significantly worse clinical status and quality of life was found in patients with white matter changes grade 3 or atrophy. Patients given full-dose RT to less volume did not have significantly less toxicity. Two cases of meningioma were found at 16 and 22 years after RT. Nineteen neuroendocrine abnormalities were observed in 16/25 patients. CONCLUSIONS External radiotherapy to the brain at a standard fractionation regime will cause varying degrees of late neurotoxicity and/or neuroendocrine disturbances in most patients. Life-long follow-up is recommended.

Vorinostat, a histone deacetylase inhibitor, combined with pelvic palliative radiotherapy for gastrointestinal carcinoma: the Pelvic Radiation and Vorinostat (PRAVO) phase 1 study.

BACKGROUND Histone deacetylase (HDAC) inhibitors have shown radiosensitising activity in preclinical tumour models. This phase 1 study assessed the use of vorinostat combined with pelvic palliative radiotherapy for gastrointestinal carcinoma. METHODS Between Feb 14, 2007, and May 18, 2009, eligible patients with histologically confirmed carcinoma, scheduled to receive pelvic palliative radiation to 30 Gy in 3 Gy daily fractions over 2 weeks, were enrolled into cohorts of escalating vorinostat dose. Vorinostat was administered orally once daily, 3 h before each radiotherapy fraction, at the following dose levels: 100 mg (n=1), 200 mg (n=4), 300 mg (n=6), and 400 mg (n=6). Endpoints included safety, tolerability, and biological activity (tumour histone acetylation). This study is registered with ClinicalTrials.gov, number NCT00455351. FINDINGS One patient withdrew consent after one treatment day, leaving 16 patients evaluable for tolerability. Most recorded adverse events were grade 1 and 2, among which fatigue (all patients) and gastrointestinal events (all patients) were most common. Grade 3 adverse events included fatigue (n=5), anorexia (n=3), diarrhoea (n=2), hyponatraemia (n=1), hypokalaemia (n=1), and acneiform rash (n=1). Of these, treatment-related grade 3 events (ie, dose-limiting toxicities) were observed in one of six patients at vorinostat 300 mg once daily (fatigue and anorexia), and in two of six patients at vorinostat 400 mg once daily (two events of diarrhoea and one each of fatigue, anorexia, hyponatraemia, and hypokalaemia). The maximum-tolerated dose of vorinostat in combination with palliative radiotherapy was thus determined to be 300 mg once daily. Histone hyperacetylation was detected, indicating biological activity of vorinostat. INTERPRETATION Vorinostat can be safely combined with short-term pelvic palliative radiotherapy. This study highlights the potential use of HDAC inhibitors with radiation, and suggests investigation of vorinostat in long-term curative pelvic radiotherapy--eg, as a component of preoperative chemoradiotherapy for rectal cancer. FUNDING Merck & Co, Inc, Norwegian Cancer Society, Norwegian Health and Rehabilitation Foundation.

Transperineal prostate biopsy detects significant cancer in patients with elevated prostate-specific antigen (PSA) levels and previous negative transrectal biopsies.

Study Type – Diagnostic (exploratory cohort)

Pharmacokinetic parameters derived from dynamic contrast enhanced MRI of cervical cancers predict chemoradiotherapy outcome

PURPOSE To assess the prognostic value of pharmacokinetic parameters derived from pre-chemoradiotherapy dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) of cervical cancer patients. MATERIALS AND METHODS Seventy-eight patients with locally advanced cervical cancer underwent DCE-MRI with Gd-DTPA before chemoradiotherapy. The pharmacokinetic Brix and Tofts models were fitted to contrast enhancement curves in all tumor voxels, providing histograms of several pharmacokinetic parameters (Brix: A(Brix), k(ep), k(el), Tofts: K(trans), ν(e)). A percentile screening approach including log-rank survival tests was undertaken to identify the clinically most relevant part of the intratumoral parameter distribution. Clinical endpoints were progression-free survival (PFS) and locoregional control (LRC). Multivariate analysis including FIGO stage and tumor volume was used to assess the prognostic significance of the imaging parameters. RESULTS A(Brix), k(el), and K(trans) were significantly (P<0.05) positively associated with both clinical LRC and PFS, while ν(e) was significantly positively correlated with PFS only. k(ep) showed no association with any endpoint. A(Brix) was positively correlated with K(trans) and ν(e), and showed the strongest association with endpoint in the log-rank testing. k(el) and K(trans) were independent prognostic factors in multivariate analysis with LRC as endpoint. CONCLUSIONS Parameters estimated by pharmacokinetic analysis of DCE-MR images obtained prior to chemoradiotherapy may be used for identifying patients at risk of treatment failure.

Prediction of response to preoperative chemoradiotherapy in rectal cancer by multiplex kinase activity profiling

PURPOSE Tumor response of rectal cancer to preoperative chemoradiotherapy (CRT) varies considerably. In experimental tumor models and clinical radiotherapy, activity of particular subsets of kinase signaling pathways seems to predict radiation response. This study aimed to determine whether tumor kinase activity profiles might predict tumor response to preoperative CRT in locally advanced rectal cancer (LARC). METHODS AND MATERIALS Sixty-seven LARC patients were treated with a CRT regimen consisting of radiotherapy, fluorouracil, and, where possible, oxaliplatin. Pretreatment tumor biopsy specimens were analyzed using microarrays with kinase substrates, and the resulting substrate phosphorylation patterns were correlated with tumor response to preoperative treatment as assessed by histomorphologic tumor regression grade (TRG). A predictive model for TRG scores from phosphosubstrate signatures was obtained by partial-least-squares discriminant analysis. Prediction performance was evaluated by leave-one-out cross-validation and use of an independent test set. RESULTS In the patient population, 73% and 15% were scored as good responders (TRG 1-2) or intermediate responders (TRG 3), whereas 12% were assessed as poor responders (TRG 4-5). In a subset of 7 poor responders and 12 good responders, treatment outcome was correctly predicted for 95%. Application of the prediction model on the remaining patient samples resulted in correct prediction for 85%. Phosphosubstrate signatures generated by poor-responding tumors indicated high kinase activity, which was inhibited by the kinase inhibitor sunitinib, and several discriminating phosphosubstrates represented proteins derived from signaling pathways implicated in radioresistance. CONCLUSIONS Multiplex kinase activity profiling may identify functional biomarkers predictive of tumor response to preoperative CRT in LARC.

Dynamic Contrast-Enhanced MRI of Cervical Cancers: Temporal Percentile Screening of Contrast Enhancement Identifies Parameters for Prediction of Chemoradioresistance

PURPOSE To systematically screen the tumor contrast enhancement of locally advanced cervical cancers to assess the prognostic value of two descriptive parameters derived from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). METHODS AND MATERIALS This study included a prospectively collected cohort of 81 patients who underwent DCE-MRI with gadopentetate dimeglumine before chemoradiotherapy. The following descriptive DCE-MRI parameters were extracted voxel by voxel and presented as histograms for each time point in the dynamic series: normalized relative signal increase (nRSI) and normalized area under the curve (nAUC). The first to 100th percentiles of the histograms were included in a log-rank survival test, resulting in p value and relative risk maps of all percentile-time intervals for each DCE-MRI parameter. The maps were used to evaluate the robustness of the individual percentile-time pairs and to construct prognostic parameters. Clinical endpoints were locoregional control and progression-free survival. The study was approved by the institutional ethics committee. RESULTS The p value maps of nRSI and nAUC showed a large continuous region of percentile-time pairs that were significantly associated with locoregional control (p < 0.05). These parameters had prognostic impact independent of tumor stage, volume, and lymph node status on multivariate analysis. Only a small percentile-time interval of nRSI was associated with progression-free survival. CONCLUSIONS The percentile-time screening identified DCE-MRI parameters that predict long-term locoregional control after chemoradiotherapy of cervical cancer.

MR-guided simultaneous integrated boost in preoperative radiotherapy of locally advanced rectal cancer following neoadjuvant chemotherapy

PURPOSE To evaluate a simultaneous integrated boost (SIB) strategy in preoperative radiotherapy of rectal cancer patients following neoadjuvant chemotherapy using pre- and post-chemotherapy tumor volumes assessed by MRI. MATERIALS AND METHODS Ten patients with locally advanced rectal cancer, receiving chemotherapy prior to radiotherapy, were included in this study. Pre- and post-chemotherapy MR tumor images were co-registered with CT images for IMRT planning. Three planning target volumes were defined: PTV(risk), PTV(pre_chemo) and PTV(post_chemo). For SIB, prescribed mean doses to the PTVs were 46, 50 and 58 Gy, respectively, given in 25 fractions. Organs at risk (OARs) were bladder and intestine. The novel three-volume SIB strategy was compared to a conventional two-volume SIB plan, in which PTV(post_chemo) was ignored, using dose-volume histograms (DVHs) and the generalized equivalent uniform dose (gEUD). RESULTS All patients showed tumor shrinkage following chemotherapy. For the novel SIB, population-based mean doses given to PTV(risk), PTV(pre_chemo) and PTV(post_chemo) were 46.8+/-0.3, 50.6+/-0.4 and 58.1+/-0.4 Gy, respectively. DVHs and gEUDs for PTV(risk), PTV(pre_chemo), bladder and intestine revealed minimal differences between the two SIB strategies. CONCLUSIONS Tumor volume reduction for rectal cancer patients following neoadjuvant chemotherapy allows for increased tumor dose using a SIB strategy without increased OAR toxicity.

Extended total mesorectal excision in locally advanced rectal cancer (T4a) and the clinical role of MRI‐evaluated neo‐adjuvant downstaging

Objective  To compare the clinical ability of MRl taken before and after neo‐adjuvant treatment in locally advanced rectal cancer (LARC) to predict the necessary extension of TME (ETME) and the possibility to achieve a R0 resection.

Magnetic resonance-guided histopathology for improved accuracy of tumor response evaluation of neoadjuvant treatment in organ-infiltrating rectal cancer

BACKGROUND AND PURPOSE The novel procedure of magnetic resonance-(MR) guided histopathology was applied to determine the false-negative rate of conventional histopathologic tumor response evaluation of neoadjuvant radiation/chemoradiation therapy (RT/CRT) in organ-infiltrating rectal cancer. MATERIALS AND METHODS Ninety-two consecutive patients that had received RT/CRT and proceeded to extended total mesorectal excision for organ-infiltrating rectal cancer were identified from the institutional database. For each patient, the study radiologist and pathologist separately interpreted preoperative MR images and histologic preparations from the surgical specimen, to determine whether tumor down-staging had resulted. In cases of discrepancy (52 patients), histologic sections were jointly reassessed for residual tumor in areas outside the mesorectal fascial compartment, using MR images as guidance for where to inspect. RESULTS Following RT/CRT, 67.5% of cases were found to remain ypT4, even though half of the study population had complete (ypT0; 7.6%) or near-complete (sparsely remaining tumor; 43.5%) histomorphologic tumor regression. After MR-guided histologic reassessment of surgical specimens, the false-negative rate of conventional histopathology for detection of ypT4 was determined to be 41.1%. Five-year estimate for locally recurrent disease was 12.7%. CONCLUSION This response data to neoadjuvant RT/CRT in organ-infiltrating rectal cancer indicate that tumor down-staging is over-estimated by conventional evaluation.

MRI volumetry for prediction of tumour response to neoadjuvant chemotherapy followed by chemoradiotherapy in locally advanced rectal cancer

OBJECTIVE To investigate if MRI-assessed tumour volumetry correlates with histological tumour response to neoadjuvant chemotherapy (NACT) and subsequent chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC). METHODS Data from 69 prospectively enrolled patients with LARC receiving NACT followed by CRT and radical surgery were analysed. Whole-tumour volumes were contoured in T2 weighted MR images obtained pre-treatment (VPRE), after NACT (VNACT) and after the full course of NACT followed by CRT (VCRT). VPRE, VNACT and tumour volume changes relative to VPRE, ΔVNACT and ΔVCRT were calculated and correlated to histological tumour regression grade (TRG). RESULTS 61% of good histological responders (TRG 1-2) to NACT followed by CRT were correctly predicted by combining VPRE < 10.5 cm(3), ΔVNACT > -78.2% and VNACT < 3.3 cm(3). The highest accuracy was found for VNACT, with 55.1% sensitivity given 100% specificity. The volume regression after completed NACT and CRT (VCRT) was not significantly different between good and poor responders (TRG 1-2 vs TRG 3-5). CONCLUSION MRI-assessed small tumour volumes after NACT correlated with good histological tumour response (TRG 1-2) to the completed course of NACT and CRT. Furthermore, by combining tumour volume measurements before, during and after NACT, more good responders were identified. ADVANCES IN KNOWLEDGE MRI volumetry may be a tool for early identification of good and poor responders to NACT followed by CRT and surgery in LARC in order to aid more individualized, multimodal treatment.