High-risk prostate cancer is traditionally treated with a combination of radiotherapy (RT) and androgen deprivation therapy (ADT). However, recent advancements in systemic treatment and radiotherapy have widened the spectrum of treatment for this patient population. Use of image guidance and intensity modulation, as well as the incorporation of brachytherapy, has led to safe radiotherapy dose escalation with reduced risk of recurrence. Clinical trials have helped define the role of pelvic nodal radiotherapy, the role of stereotactic ablative radiotherapy, and the optimal duration and sequencing of ADT in combination with radiotherapy. Emerging evidence has redefined the role of surgery in this cohort. Contemporary clinical trials have identified new systemic therapy options in high-risk prostate cancer. Finally, new imaging modalities including multi-parametric MRI and molecular imaging and genomic classifiers have ushered a new era in patient selection, risk stratification, and treatment tailoring.
1 January 2021 in Physics and Imaging in Radiation Oncology
Cranial irradiation is associated with significant neurocognitive sequelae, secondary to radiation-induced damage to hippocampal cells. It has been shown that hippocampal-sparing (HS) leads to modest benefit in neurocognitive function in patients with brain metastases, but further improvement is possible. We hypothesized that improved benefits could be seen using HS in patients treated with stereotactic radiation (HS-SRS). Our study evaluated whether the hippocampal dose could be significantly reduced in the treatment of brain metastases using SRS, while maintaining target coverage. Sixty SRS plans were re-planned to minimize dose to the hippocampus while maintaining target coverage. Patients with metastases within 5 mm of the hippocampus were excluded. Minimum, mean, maximum and dose to 40% (mean equivalent dose in 2 Gy per fraction, EQD2 to the hippocampus) were compared between SRS and HS-SRS plans. Median number of brain metastases was two. Compared to baseline SRS plans, hippocampal-sparing plans demonstrated Dmin was reduced by 35%, from 0.4 Gy to 0.3 Gy (p-value 0.02). Similarly, Dmax was reduced by 55%, from 8.2 Gy to 3.6 Gy, Dmean by 52%, from 1.6 Gy to 0.5 Gy, and D40 by 50%, from 1.8 Gy to 0.9 Gy (p-values <0.001). Our study demonstrated that further reduction of hippocampal doses of more than 50% is possible in the treatment of brain metastases with SRS using dose optimization. This could result in significantly improved neurocognitive outcomes for patients treated for brain metastases.
Craniopharyngiomas can invade surrounding structures, including the optic chiasm and hypothalamus. In such cases, subtotal resection is often preferred to limit perioperative morbidity and mortality; however, subtotal resection is associated with high rates of recurrence. Recurrent craniopharyngioma is typically treated with another subtotal resection and adjuvant radiotherapy. We present a case of a patient found to have a large craniopharyngioma compressing the optic chiasm, hypothalamus and left cavernous sinus. She underwent surgical debulking but developed recurrence shortly thereafter. Subsequently, she underwent a second debulking surgery, followed by fractionated stereotactic radiotherapy (SRT). Results show that she exhibited an impressive response to SRT with further tumor shrinkage, while remaining clinically well. This case demonstrates the efficacy of SRT in salvage of recurrent craniopharyngioma.
Approximately 20% of renal cell carcinoma (RCC) is diagnosed because of paraneoplastic manifestations. RCC has been associated with a large variety of paraneoplastic syndromes (PNS), but it is rarely associated with PNS vasculitis. We present a case of a previously healthy male who presented with systemic vasculitis; bitemporal headaches, diplopia, polyarthritis, palpable purpura, tongue lesion, peri-orbital edema, scleritis, chondritis and constitutional symptoms. He was subsequently found to have oligometastatic RCC. Both his primary lesion and site of oligometastasis were treated with stereotactic radiotherapy (SBRT) and resulted in the resolution of his vasculitis, as well as sustained oncologic response. This is the first case to demonstrate that effective sustained treatment for PNS vasculitis due to oligometastatic RCC is possible with SBRT.