Patients with locally advanced oropharynx squamous cell carcinoma have suboptimal outcomes with standard chemoradiation. Here, we evaluated toxicity and oncologic outcomes of dose escalation using ...radiosurgical boost for patients with unfavorable oropharynx squamous cell carcinoma.
Between 2010-2017, Thirty four patients with intermediate- or high-risk oropharynx squamous cell carcinoma were enrolled onto this prospective phase I trial. Each patient received concurrent cisplatin and fractionated radiotherapy totaling 60 Gy or 66 Gy followed by radiosurgery boost to areas of residual gross tumor: single fraction of 8 Gy or 10 Gy, or two fractions of 5 Gy each. Primary endpoint was treatment toxicity. Secondary endpoints were local, regional, and distant disease control.
Eleven, sixteen and seven patients received radiosurgery boost with 8 Gy in 1 fraction, 10 Gy in 1 fraction, and 10 Gy in 2 fractions respectively. Acute toxicities include 4 patients with tumor necrosis causing grade 3 dysphagia, of which 3 developed grade 4 pharyngeal hemorrhage requiring surgical intervention. At 24 months after treatment, 7%, 9%, and 15% had grade 2 dysgeusia, xerostomia, and dysphagia, respectively, and two patients remained feeding tube dependent. No grade 5 toxicities occurred secondary to treatment. Local, regional, and distant control at a median follow up of 4.2 years were 85.3%, 85.3% and 88.2%, respectively. Five patients died resulting in overall survival of 85.3%.
This study is the first to report the use of radiosurgery boost dose escalation in patients with unfavorable oropharynx squamous cell carcinoma. Longer follow-up, larger cohorts, and further refinement of boost methodology are needed prior to implementation in routine clinical practice.
Northwell Health Protocol #09-309A (NCT02703493) ( https://clinicaltrials.gov/ct2/show/NCT02703493 ).
The median survival duration for patients with glioblastoma is approximately 12 months. Maximizing quality of life (QOL) for patients with glioblastoma is a priority. An important, yet understudied, ...QOL component is functional independence. The aims of this study were to evaluate functional outcomes over time for patients with glioblastoma, as well as identify factors associated with prolonged functional independence.
All patients who underwent first-time resection of either a primary (de novo) or secondary (prior lower grade glioma) glioblastoma at a single institution from 1996 to 2006 were retrospectively reviewed. Patients with a Karnofsky Performance Scale (KPS) score ≥ 80 were included. Kaplan-Meier, log-rank, and multivariate proportional hazards regression analyses were used to identify associations (p < 0.05) with functional independence (KPS score ≥ 60) following glioblastoma resection.
The median follow-up duration time was 10 months (interquartile range IQR 5.6-17.0 months). A patient's preoperative (p = 0.02) and immediate postoperative (within 2 months) functional status was associated with prolonged survival (p < 0.0001). Of the 544 patients in this series, 302 (56%) lost their functional independence at a median of 10 months (IQR 6-16 months). Factors independently associated with prolonged functional independence were: preoperative KPS score ≥ 90 (p = 0.004), preoperative seizures (p = 0.002), primary glioblastoma (p < 0.0001), gross-total resection (p < 0.0001), and temozolomide chemotherapy (p < 0.0001). Factors independently associated with decreased functional independence were: older age (p < 0.0001), coexistent coronary artery disease (p = 0.009), and incurring a new postoperative motor deficit (p = 0.009). Furthermore, a decline in functional status was independently associated with tumor recurrence (p = 0.01).
The identification and consideration of these factors associated with prolonged functional outcome (preoperative KPS score ≥ 90, seizures, primary glioblastoma, gross-total resection, temozolomide) and decreased functional outcome (older age, coronary artery disease, new postoperative motor deficit) may help guide treatment strategies aimed at improving QOL for patients with glioblastoma.
To present evidence-based guidelines for the treatment of oropharyngeal squamous cell carcinoma (OPSCC) with definitive or adjuvant radiation therapy (RT).
The American Society for Radiation Oncology ...convened the OPSCC Guideline Panel to perform a systematic literature review investigating the following key questions: (1) When is it appropriate to add systemic therapy to definitive RT in the treatment of OPSCC? (2) When is it appropriate to deliver postoperative RT with and without systemic therapy following primary surgery for OPSCC? (3) When is it appropriate to use induction chemotherapy in the treatment of OPSCC? (4) What are the appropriate dose, fractionation, and volume regimens with and without systemic therapy in the treatment of OPSCC?
Patients with stage IV and stage T3 N0-1 OPSCC treated with definitive RT should receive concurrent high-dose intermittent cisplatin. Patients receiving adjuvant RT following surgical resection for positive surgical margins or extracapsular extension should be treated with concurrent high-dose intermittent cisplatin, and individuals with these risk factors who are intolerant of cisplatin should not routinely receive adjuvant concurrent systemic therapy. Induction chemotherapy should not be routinely delivered to patients with OPSCC. For patients with stage IV and stage T3 N0-1 OPSCC ineligible for concurrent chemoradiation therapy, altered fractionation RT should be used.
The successful management of OPSCC requires the collaboration of radiation, medical, and surgical oncologists. When high-level data are absent for clinical decision-making, treatment recommendations should incorporate patient values and preferences to arrive at the optimal therapeutic approach.
Abstract Glioblastoma multiforme (GBM) is the most common primary brain tumour in the United States of America (USA) with a median survival of approximately 14 months. Low survival rates are ...attributable to the aggressiveness of GBM and a lack of understanding of the molecular mechanisms underlying GBM. The disruption of signalling pathways regulated either directly or indirectly by protein kinases is frequently observed in cancer cells and thus the development of inhibitors of specific kinases has become a major focus of drug discovery in oncology. To identify protein kinases required for the survival of GBM we performed a siRNA-based RNAi screen focused on the human kinome in GBM. Inhibition of the polo-like kinase 1 ( PLK1 ) induced a reduction in the viability in two different GBM cell lines. To assess the potential of inhibiting PLK1 as a treatment strategy for GBM we examined the effects of a small molecule inhibitor of PLK1, GSK461364A, on the growth of GBM cells. PLK1 inhibition arrested cells in the mitotic phase of the cell cycle and induced cell kill by mitotic catastrophe. GBM engrafts treated with GSK461364A showed statistically significant inhibition of tumour growth. Further, exposure of different GBM cells to RNAi or GSK461364A prior to radiation resulted in an increase in their radiosensitivity with dose enhancement factor ranging from 1.40 to 1.53 with no effect on normal cells. As a measure of DNA double strand breaks, γH2AX levels were significantly higher in the combined modality as compared to the individual treatments. This study suggests that PLK1 is an important therapeutic target for GBM and can enhance radiosensitivity in GBM.
This study aimed to quantitatively evaluate the range uncertainties that arise from daily cone-beam CT (CBCT) images for proton dose calculation compared to CT using a measurement-based technique.
...For head and thorax phantoms, wedge-shaped intensity-modulated proton therapy (IMPT) treatment plans were created such that the gradient of the wedge intersected and was measured with a 2D ion chamber array. The measured 2D dose distributions were compared with 2D dose planes extracted from the dose distributions using the IMPT plan calculated on CT and CBCT. Treatment plans of a thymoma cancer patient treated with breath-hold (BH) IMPT were recalculated on 28 CBCTs and 9 CTs, and the resulting dose distributions were compared.
The range uncertainties for the head phantom were determined to be 1.2% with CBCT, compared to 0.5% for CT, whereas the range uncertainties for the thorax phantom were 2.1% with CBCT, compared to 0.8% for CT. The doses calculated on CBCT and CT were similar with similar anatomy changes. For the thymoma patient, the primary source of anatomy change was the BH uncertainty, which could be up to 8 mm in the superior-inferior (SI) direction.
We developed a measurement-based range uncertainty evaluation method with high sensitivity and used it to validate the accuracy of CBCT-based range and dose calculation. Our study demonstrated that the CBCT-based dose calculation could be used for daily dose validation in selected proton patients.
To compare spatially fractionated radiation therapy (GRID) treatment planning techniques using proton pencil-beam-scanning (PBS) and photon therapy.
PBS and volumetric modulated arc therapy (VMAT) ...GRID plans were retrospectively generated for 5 patients with bulky tumors. GRID targets were arranged along the long axis of the gross tumor, spaced 2 and 3 cm apart, and treated with a prescription of 18 Gy. PBS plans used 2- to 3-beam multiple-field optimization with robustness evaluation. Dosimetric parameters including peak-to-edge ratio (PEDR), ratio of dose to 90% of the valley to dose to 10% of the peak VPDR(D90/D10), and volume of normal tissue receiving at least 5 Gy (V5) and 10 Gy (V10) were calculated. The peak-to-valley dose ratio (PVDR), VPDR(D90/D10), and organ-at-risk doses were prospectively assessed in 2 patients undergoing PBS-GRID with pretreatment quality assurance computed tomography (QACT) scans.
PBS and VMAT GRID plans were generated for 5 patients with bulky tumors. Gross tumor volume values ranged from 826 to 1468 cm
. Peak-to-edge ratio for PBS was higher than for VMAT for both spacing scenarios (2-cm spacing,
= .02; 3-cm spacing,
= .01). VPDR(D90/D10) for PBS was higher than for VMAT (2-cm spacing,
= .004; 3-cm spacing,
= .002). Normal tissue V5 was lower for PBS than for VMAT (2-cm spacing,
= .03; 3-cm spacing,
= .02). Normal tissue mean dose was lower with PBS than with VMAT (2-cm spacing,
.03; 3-cm spacing,
.02). Two patients treated using PBS GRID and assessed with pretreatment QACT scans demonstrated robust PVDR, VPDR(D90/D10), and organs-at-risk doses.
The PEDR was significantly higher for PBS than VMAT plans, indicating lower target edge dose. Normal tissue mean dose was significantly lower with PBS than VMAT. PBS GRID may result in lower normal tissue dose compared with VMAT plans, allowing for further dose escalation in patients with bulky disease.
Recent single institution, phase II evidence has demonstrated the feasibility and efficacy of ultra-hypofractionated, preoperative photon therapy in 5 fractions for the treatment of soft tissue ...sarcoma (STS). Our purpose was to evaluate the dosimetric benefits of modern scanning beam proton therapy compared with conventional photon radiation therapy (RT) for the neoadjuvant treatment of adult extremity STS.
Existing proton and photon plans for 11 adult patients with STS of the lower extremities previously treated preoperatively with neoadjuvant RT at our center were used to create proton therapy plans using Raystation Treatment Planning System v10.A. Volumes were delineated, and doses reported consistent with International Commission on Radiation Units and Measurements reports 50, 62, and 78. Target volumes were optimized such that 100% clinical target volume (CTV) was covered by 99% of the prescription dose. The prescribed dose was 30 Gy for PT and RT delivered in 5 fractions. For proton therapy, doses are reported in GyRBE = 1.1 Gy. The constraints for adjacent organs at risk (OARs) within 1 cm of the CTV were the following: femur V30Gy ≤ 50%, joint V30Gy < 50%, femoral head V30Gy ≤ 5 cm
, strip V12 ≤ 10%, and skin V12 < 50%. Target coverage goals, OAR constraints, and integral dose were compared by Student
test with
< .05 significance.
A minimum 99% CTV coverage was achieved for all plans. OAR dose constraints were achieved for all proton and photon plans; however, mean doses to the femur (10.7 ± 8.5 vs 16.1 ± 7.7 GyRBE), femoral head (2.0 ± 4.4 vs 3.6 ± 6.4 GyRBE), and proximal joint (1.8 ± 2.4 vs 3.5 ± 4.4 GyRBE) were all significantly lower with PT vs intensity-modulated radiation therapy (IMRT) (all
< .05). Integral dose was significantly reduced for proton vs photon plans. Conformity and heterogeneity indices were significantly better for proton therapy.
Proton therapy maintained target coverage while significantly reducing integral and mean doses to the proximal organs at risk compared with RT. Further prospective investigation is warranted to validate these findings and potential benefit in the management of adult STS.
Limited data exist comparing intensity-modulated photon (IMRT) and proton (IMPT) radiation therapy when treating the prostate bed and pelvic lymph nodes in the postoperative setting for prostate ...cancer. The aim of this study was to evaluate dosimetric differences between IMRT and IMPT when treating with whole pelvis radiation therapy (WPRT) postoperatively.
IMRT and IMPT plans were generated for 10 post-prostatectomy patients treated between July and August 2020. The prescription was 50 Gy radiobiologic equivalent (GyE) (proton radiobiological effective dose 1.1) to the pelvis and 70 GyE to the prostate bed in 2 GyE per fraction. Paired 2-sided Wilcoxon signed-rank tests were used to compare clinical target volume (CTV) coverage and dose to organs at risk (OARs).
CTV coverage was met for all plans with 99% of CTVs receiving ≥99% of prescription doses. Dose to OARs was significantly higher with IMRT than IMPT for the following endpoints: bladder V5-V65; bowel V5-V45; sigmoid V5-V50; rectum V5-V70; femoral head V40 and maximum dose; bone V5-V65. Select endpoints with significant differences included bladder V30 (63.5 vs. 44.4%, p < .001), bowel V15 (949 vs. 191 cc, p = .001) and V30 (386 vs. 121 cc, p < .001), rectum V40 (81.8 vs. 32.1%, p < .001) and V50 (47.6 vs. 24.9%, p < .001), femoral head maximum doses (46.4-47.1 vs. 38.3-38.6GyE, p < .001), and bone V10 (93.3 vs. 85.4%, p < . 001). Mean doses for all OARs were significantly higher with IMRT, including bladder (41.9 vs. 29.7GyE, p < .001), bowel (21.2 vs. 5.5GyE, p < .001), and rectum (50.8 vs. 27.3GyE, p < .001). Integral dose to 'Body - CTV' was significantly higher with IMRT (32.8 vs. 18.4 J, p < .001).
IMPT provides comparable target coverage to IMRT when treating prostate cancer with WPRT in the postoperative setting while significantly reducing dose to OARs. These data can inform the future clinical management and delivery of post-prostatectomy irradiation for prostate cancer.
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