Linxin Guo

Image‐guided dose‐escalated intensity‐modulated radiation therapy for prostate cancer: treating to doses beyond 78 Gy

Study Type – Therapy (case series)

Neutrophil‐to‐lymphocyte ratio in head and neck cancer

The neutrophil‐to‐lymphocyte ratio (NLR) is an index of systemic inflammatory burden in malignancy. An elevated NLR has been associated with poor prognosis in a number of cancer sites. We investigated its role in a cohort of patients with locally advanced head and neck cancer.

Feasibility of and rectal dosimetry improvement with the use of SpaceOAR® hydrogel for dose‐escalated prostate cancer radiotherapy

The aim of this study was to investigate the feasibility of injecting a temporary spacer between the rectum and the prostate and to quantify the degree of rectal dosimetric improvement that might result.

Health-related quality of life using intensity-modulated radiation therapy for post-prostatectomy radiotherapy

Post‐prostatectomy radiotherapy (PPRT) with intensity‐modulated radiation therapy (IMRT) has the potential to decrease toxicity by reducing dose to surrounding structures. We assessed its impact on health‐related quality of life (HRQoL).

Volumetric-modulated arc therapy in postprostatectomy radiotherapy patients: A planning comparison study

The purpose of this study was to compare postprostatectomy planning for volumetric-modulated arc therapy (VMAT) with both single arc (SA) and double arcs (DA) against dynamic sliding window intensity-modulated radiotherapy (IMRT). Ten cases were planned with IMRT, SA VMAT, and DA VMAT. All cases were planned to achieve a minimum dose of 68Gy to 95% of the planning target volume (PTV) and goals to limit rectal volume >40Gy to 35% and >65Gy to 17%, and bladder volumes >40Gy to 50% and >65Gy to 25%. Plans were averaged across the 10 patients and compared for mean dose, conformity, homogeneity, rectal and bladder doses, and monitor units. The mean dose to the clinical target volume and PTV was significantly higher (p<0.05) for SA compared with DA or IMRT. The homogeneity index was not significantly different: SA = 0.09; DA = 0.08; and IMRT = 0.07. The rectal V40 was lowest for the DA plan. The rectal V20 was significantly lower (p<0.05) for both the VMAT plans compared with IMRT. There were no significant differences for bladder V40 or rectal and bladder V65. The IMRT plans required 1400MU compared with 745 for DA and 708 for SA. This study shows that for equivalent dose coverage, SA and DA VMAT plans result in higher mean doses to the clinical target volume and PTV. This greater dose heterogeneity is balanced by improved low-range rectal doses and halving of the monitor units.

68Ga-PSMA-PET/CT staging prior to definitive radiation treatment for prostate cancer

To explore the utility of prostate specific membrane antigen (PSMA)‐positron emission tomography (PET)/computed tomography (CT) in addition to conventional imaging prior to definitive external beam radiation treatment (EBRT) for prostate cancer.

Intensity-modulated radiotherapy using simultaneous-integrated boost for definitive treatment of locally advanced mucosal head and neck cancer: Outcomes from a single-institution series

The study aims to report outcomes for patients treated using intensity‐modulated radiotherapy (IMRT) with simultaneous‐integrated boost and weekly cisplatin for American Joint Committee on Cancer stage III/IV mucosal head and neck squamous cell carcinomas (HNSCCs).

Survival improvements with adjuvant therapy in patients with glioblastoma

Evaluate survival of patients diagnosed with glioblastoma multiforme (GBM) managed with adjuvant intensity modulated radiation therapy and temozolomide since the introduction of the European Organisation for Research and Treatment of Cancer and National Cancer Institute of Canada Clinical Trials Group (EORTC‐NCIC) protocol.

Delineating sites of failure following post-prostatectomy radiation treatment using 68 Ga-PSMA-PET

PURPOSE To identify sites of failure with 68Ga-PSMA-PET (PSMA-PET) imaging in patients who have Biochemical Failure (BF) following post-prostatectomy radiotherapy. MATERIAL AND METHODS Between June 2006 and January 2016, 409 men received post prostatectomy intensity modulated radiation treatment (IMRT) with protocolised planning. 310 patients received radiation treatment (RT) to the Prostate Fossa (PF) alone and 99 patients received RT to PF and pelvic lymphatics (PF + LN) usually in combination with androgen deprivation (AD) therapy. Any failure not detected on conventional imaging was delineated with PSMA-PET scanning. Sites of failure were characterised as in-field (PF ± LN), or out of field (nodal alone, distant metastatic alone (visceral or bone) or multi-site failure). Nodal failure was further divided into pelvic failure and/or distant failure. RESULTS 119 men developed BF, defined as a PSA rise of >0.2 or greater, above post-RT nadir. Freedom from BF was 71% in the PF group and 70% in the PF + LN group, with median follow up of 52 and 44 months respectively. AD was used concomitantly in 13% of the PF group and 92% of the PF + LN group. 81 patients with BF (68%) had PSMA-PET imaging performed as per study intent, 67 (80%) of whom had PSMA avid disease identified. PSMA-PET delineated in-field failure occurred in 2/50 (4%) of the PF group and 1/17 (6%) in the PF + LN group. Nodal failure alone was 33/50 (66%) for the PF group vs 7/17 (41%) for the PF + LN group. For the nodal only failure patients, 18/33 (55%) had pelvic-only nodal failure in the PF group compared to 1/7 (14%) in the PF + LN group (p = 0.03). 16 (32%) of the PSMA avid failures in the PF group would have been encompassed by standard pelvic lymphatic radiotherapy volumes. CONCLUSION Post-prostatectomy radiation treatment resulted in excellent in-field control rates. Isolated pelvic nodal failure was rare in those receiving radiotherapy to the prostatic fossa and pelvic nodes but accounted for one third of failures in those receiving PF alone treatment.

Optimising Outcomes for Glioblastoma through Subspecialisation in a Regional Cancer Centre

Delivery of highly sophisticated, and subspecialised, management protocols for glioblastoma in low volume rural and regional areas creates potential issues for equivalent quality of care. This study aims to demonstrate the impact on clinical quality indicators through the development of a novel model of care delivering an outsourced subspecialised neuro-oncology service in a regional centre compared with the large volume metropolitan centre. Three hundred and fifty-two patients with glioblastoma were managed under the European Organisation for Research and Treatment of Cancer and National Cancer Institute of Canada Clinical Trials Group (EORTC-NCIC) Protocol, and survival outcome was assessed in relation to potential prognostic factors and the geographical site of treatment, before and after opening of a regional cancer centre. The median overall survival was 17 months (95% CI: 15.5–18.5), with more favourable outcome with age less than 50 years (p < 0.001), near-total resection (p < 0.001), Eastern Cooperative Oncology Group (ECOG) Performance status 0, 1 (p < 0.001), and presence of O-6 methylguanine DNA methyltransferase (MGMT) methylation (p = 0.001). There was no difference in survival outcome for patients managed at the regional centre, compared with metropolitan centre (p = 0.35). Similarly, no difference was seen with clinical quality process indicators of clinical trial involvement, rates of repeat craniotomy, use of bevacizumab and re-irradiation. This model of neuro-oncology subspecialisation allowed equivalent outcomes to be achieved within a regional cancer centre compared to large volume metropolitan centre.