AbstractBackgroundThe objective of this study was to report acute changes in patient‐reported quality of life (PRQOL) using the 26‐item Expanded Prostate Index Composite (EPIC‐26) questionnaire in a prospective study using hypofractionated intensity‐modulated proton beam therapy (H‐IMPT) targeting the prostate and the pelvic lymph nodes for high‐risk or unfavorable intermediate‐risk prostate cancer.MethodsFifty‐five patients were enrolled. H‐IMPT consisted of 45 GyE to the pelvic lymph nodes and 67.5 GyE to the prostate and seminal vesicles in 25 fractions. PRQOL was assessed with the urinary incontinence (UI), urinary irritative/obstructive symptoms (UO), and bowel function (BF) domains of EPIC‐26 questionnaire. Mean changes in domain scores were analyzed from pretreatment to the end of treatment and 3 months posttreatment. A clinically meaningful change (or minimum important change) was defined as a score change > 50% of the baseline standard deviation.ResultsThe mean scores of UO, UI, and BF at baseline were 84.6, 91.1, and 95.3, respectively. At the end of treatment, there were statistically significant and clinically meaningful declines in UO and BF scores (−13.5 and −2.3, respectively), while the decline in UI score was statistically significant but not clinically meaningful (−13.7). A clinically meaningful decline in UO, UI, and BF scores occurred in 53.5%, 22.7%, and 73.2% of the patients, respectively. At 3 months posttreatment, all three mean scores showed an improvement, with fewer patients having a clinically meaningful decline in UO, UI, and BF scores (18.4%, 20.5%, and 45.0%, respectively). There was no significant reduction in the mean UO and UI scores compared to baseline, although the mean BF score remained lower than baseline and the difference was clinically meaningful.ConclusionsUO, UI, and BF scores of PRQOL declined at the end of H‐IMPT. UO and UI scores showed improvement at 3 months posttreatment and were similar to the baseline scores. However, BF score remained lower at 3 months posttreatment with a clinically meaningful decline.
A phase II trial of hypofractionated radiation therapy over five treatments for prostate cancer with high-risk features after radical prostatectomy: MC1754.
248 Background: Hypofractionated prostate cancer radiation has showed similar results in several prior phase III studies (PCG GU 003, PACE-B, and Hypo PC RT). However, prospective phase II-III clinical trial data testing 5 tx after prostatectomy is scarce. Methods: Between 2018 and 2019, 41 patients were treated after postprostatectomy for high risk features. 5 patients were treated adjuvantly, 36 for salvage including 8 with oligometastatic disease. Indications for adjuvant RT included a PSA < 0.2 and +margins, SVI, or EPE. Salvage RT was offered for PSA ≥0.2. Oligometastatic RT for patients with ≤5 RT targets. Staging included C11 PET for all cases. Total dose to the prostate bed was 30-32 Gy in 5tx QOD with IMRT, conebeam IGRT, and MRI registration. All salvage patients received ADT for 6 months and oligometastatic patients for 18 months. Dose to the metastatic sites was 30 in 5tx QOD. Of the 41 patients 8 also received SBRT to the sites of oligometastatic disease. We looked at clinical outcomes defining biochemical failure as a PSA > 0.2 after treatment, baseline adjusted CTC AE V5.0, baseline adjusted patient reported toxicities (PRO CTC AE), QOL (EPIC, PROMIS), and AUA was used for all cases. Results: Median follow up was 23 months (range 10-37). Pre-RT T stage was T2-T3b, with 47% being T3a-b; Pre RT Median PSA of 0.4 (range < 0.1-1.9); Median GS 8 (6-9); and (+) margins in 48.8%. Sites of oligometastatic disease radiated included the LN and bone. Treatment related AE were grade 0-1 in all cases, except for one patient with G2 GU incontinence. Overall QOL remained high during follow including Promis 10 overall, mental, and physical scores; urinary bother, irritative/obstructive, and AUA scores; bowel overall, bowel bother, and bowel function scores; and overall sexual, sexual function, and sexual bother scores remained at baseline levels during follow up. Only hormonal overall, hormonal function, and hormonal bother had lower scores at 3 months that recovered by 12 months in patients treated with ADT for 6 months and by 24 months in patients treated with ADT for 18 months. A total of 3 clinical failure have been seen; 2 patients with regional failures alone; and one with axial skeleton bony failures for 93% clinical control at median follow up of 23 months. All 3 patients with clinical failure were salvaged successfully with SBRT and all patients remain disease free at last follow up. A total 5 patients with raising PSAs alone have been seen. All patients have been re-staged with C11 PET. No failures in the prostate bed or previously radiated sites have been seen. Conclusions: Toxicity for RT over 5tx is lower than expected with only one case of grade 2 urinary incontinence. QOL scores remained high during follow up, minor changes in hormonal scores were seen during ADT, but recovered after. 30-32 Gy over 5 tx provided 100% control in radiated targets and metastatic sites. Clinical trial information: NCT03570827.
Technical Note: Multiple energy extraction techniques for synchrotron‐based proton delivery systems may exacerbate motion interplay effects in lung cancer treatments
Abstract Purpose The multiple energy extraction (MEE) delivery technique for synchrotron‐based proton delivery systems reduces beam delivery time by decelerating the beam multiple times during one accelerator spill, but this might cause additional plan quality degradation due to intrafractional motion. We seek to determine whether MEE causes significantly different plan quality degradation compared to single energy extraction (SEE) for lung cancer treatments due to the interplay effect. Methods Ten lung cancer patients treated with IMPT at our institution were nonrandomly sampled based on a representative range of tumor motion amplitudes, tumor volumes, and respiratory periods. Dose‐volume histogram (DVH) indices from single‐fraction SEE and MEE four‐dimensional (4D) dynamic dose distributions were compared using the Wilcoxon signed‐rank test. Distributions of monitor units (MU) to breathing phases were investigated for features associated with plan quality degradation. SEE and MEE DVH indices were compared in fractionated deliveries of the worst‐case patient treatment scenario to evaluate the impact of fractionation. Results There were no clinically significant differences in target mean dose, target dose conformity, or dose to organs‐at‐risk between SEE and MEE in single‐fraction delivery. Three patients had significantly worse dose homogeneity with MEE compared to SEE (single‐fraction mean D 5% ‐D 95% increased by up to 9.6% of prescription dose), and plots of MU distribution to breathing phases showed synchronization patterns with MEE but not SEE. However, after 30 fractions the patient in the worst‐case scenario had clinically acceptable target dose homogeneity and coverage with MEE (mean D 5% –D 95% increased by 1% compared to SEE). Conclusions For some patients with breathing periods close to the mean spill duration, MEE resulted in significantly worse single‐fraction target dose homogeneity compared to SEE due to the interplay effect. However, this was mitigated by fractionation, and target dose homogeneity and coverage were clinically acceptable after 30 fractions with MEE.
Intensity‐modulated proton therapy (IMPT) interplay effect evaluation of asymmetric breathing with simultaneous uncertainty considerations in patients with non‐small cell lung cancer
Purpose Intensity‐modulated proton therapy (IMPT) is sensitive to uncertainties from patient setup and proton beam range, as well as interplay effect. In addition, respiratory motion may vary from cycle to cycle, and also from day to day. These uncertainties can severely degrade the original plan quality and potentially affect patient’s outcome. In this work, we developed a new tool to comprehensively consider the impact of all these uncertainties and provide plan robustness evaluation under them. Methods We developed a comprehensive plan robustness evaluation tool that considered both uncertainties from patient setup and proton beam range, as well as respiratory motion simultaneously. To mimic patients' respiratory motion, the time spent in each phase was randomly sampled based on patient‐specific breathing pattern parameters as acquired during the four‐dimensional (4D)‐computed tomography (CT) simulation. Spots were then assigned to one specific phase according to the temporal relationship between spot delivery sequence and patients’ respiratory motion. Dose in each phase was calculated by summing contributions from all the spots delivered in that phase. The final 4D dynamic dose was obtained by deforming all doses in each phase to the maximum exhalation phase. Three hundred (300) scenarios (10 different breathing patterns with 30 different setup and range uncertainty scenario combinations) were calculated for each plan. The dose‐volume histograms (DVHs) band method was used to assess plan robustness. Benchmarking the tool as an application’s example, we compared plan robustness under both three‐dimensional (3D) and 4D robustly optimized IMPT plans for 10 nonrandomly selected patients with non‐small cell lung cancer. Results The developed comprehensive plan robustness tool had been successfully applied to compare the plan robustness between 3D and 4D robustly optimized IMPT plans for 10 lung cancer patients. In the presence of interplay effect with uncertainties considered simultaneously, 4D robustly optimized plans provided significantly better CTV coverage (D 95% , P = 0.002), CTV homogeneity (D 5% ‐D 95% , P = 0.002) with less target hot spots (D 5% , P = 0.002), and target coverage robustness (CTV D 95% bandwidth, P = 0.004) compared to 3D robustly optimized plans. Superior dose sparing of normal lung (lung D mean , P = 0.020) favoring 4D plans and comparable normal tissue sparing including esophagus, heart, and spinal cord for both 3D and 4D plans were observed. The calculation time for all patients included in this study was 11.4 ± 2.6 min. Conclusion A comprehensive plan robustness evaluation tool was successfully developed and benchmarked for plan robustness evaluation in the presence of interplay effect, setup and range uncertainties. The very high efficiency of this tool marks its clinical adaptation, highly practical and versatile nature, including possible real‐time intra‐fractional interplay effect evaluation as a potential application for future use.
Expanding the Spectrum of Radiation Necrosis After Stereotactic Radiosurgery (SRS) for Intracranial Metastases From Lung Cancer
Objective:Radiation therapy (RT) is the primary treatment of intracranial metastasis (ICM) from lung cancer (LC). Radiation necrosis (RN) has been reported post-RT with an incidence of 5% to 24%. We reviewed the spectrum of imaging changes in patients treated with RT for ICM from LC in an effort to identify potential risk factors for RN.Methods:We reviewed 63 patients with LC and ICM who received RT (radiosurgery [stereotactic radiosurgery] with/without whole brain radiation therapy) at our institution between 2013 and 2018. Data evaluated included demographics, tumor type, ICM burden and location, chemotherapy, surgery, and RT details as well as treatment choices and outcomes.Results:Of the 63 patients, clinical and radiographic criteria for RN were noted in 24 (38%) as early as 2 months and as late as 5 years posttreatment. Six patients required surgical resection due to refractory symptoms revealing pathology-proven RN and occasionally tumor. Patients were significantly more likely to develop RN if they had surgical resection of an ICM (45.8% vs. 20.5%,P=0.05). No differences were found in location, size, or genetic profile of lesions. In total, 80% of patients received treatment for symptoms and/or radiographic change. This was generally a combination of steroids, bevacizumab, laser interstitial thermal treatment, or surgical resection. Most patients required >1 treatment modality.Conclusions:This review of outcomes of RT for ICM in LC demonstrates a higher rate of RN than previously reported in the literature in those having had a surgical resection plus stereotactic radiosurgery. Our observation of RN as late as 5 years post-RT for ICM necessitates clinician awareness.
CMET-05. EVALUATING RADIATION NECROSIS IN PATIENTS WITH INTRACRANIAL METASTASES FROM MELANOMA
Abstract BACKGROUND Radiation is an integral component of the multidisciplinary treatment of patients with intracranial metastasis (ICM) from melanoma. The risk of radiation necrosis (RN) post-treatment can range from 5–25%. We retrospectively evaluated pre- and post-radiation clinical and radiographical characteristics in patients with ICM from melanoma to identify potential risk factors for RN. METHODS After IRB approval, patients with ICM from melanoma who received radiation at our institution between 2013 and 2018 were retrospectively reviewed. We recorded demographics, intracranial metastasis (burden and location), systemic therapy, resection, stereotactic radiosurgery versus whole brain radiation, and outcomes. Brain MRI was evaluated using the Response Assessment in Neuro-Oncology criteria (RANO). RESULTS A total of 27 patients were included in the study. RN was diagnosed in 14 patients (52%) at one month to three years following radiation. Cerebellar location (n=7) was significantly associated with RN (p=0.0058). Metastasis-associated hemorrhage was present in 7 patients, 6 of which developed RN (43% vs 8%, p=0.08). Surgical resection prior to radiation was performed in 9 patients, 7 of which developed RN (50% vs 15%, p=0.1). RN appeared to be less often diagnosed when ICM were treated with higher doses of radiation (24 Gy vs 20 Gy, p=0.07). Systemic treatment was administered prior to radiation in 25 patients and we found no relationship with systemic therapy type and RN. Presumed RN was treated in 12 of 14 patients (86%). Steroids or surgical resection were the primary treatment modalities, with laser ablation used in 1 case. Following treatment, improvement was noted in 3 patients radiographically and in 1 of these clinically. CONCLUSIONS This series of patients with radiotherapy-treated brain metastases from melanoma reveals cerebellar involvement, hemorrhage, and prior surgical resection as potential risk factors for radiation necrosis. Neoadjuvant systemic treatment did not appear to be a risk factor in our review.
Technical Note: Treatment planning system (TPS) approximations matter — comparing intensity‐modulated proton therapy (IMPT) plan quality and robustness between a commercial and an in‐house developed TPS for nonsmall cell lung cancer (NSCLC)
PurposeApproximate dose calculation methods were used in the nominal dose distribution and the perturbed dose distributions due to uncertainties in a commercial treatment planning system (CTPS) for robust optimization in intensity‐modulated proton therapy (IMPT). We aimed to investigate whether the approximations influence plan quality, robustness, and interplay effect of the resulting IMPT plans for the treatment of locally advanced lung cancer patients.Materials and methodsTen consecutively treated locally advanced nonsmall cell lung cancer (NSCLC) patients were selected. Two IMPT plans were created for each patient using our in‐house developed TPS, named “Solo,” and also the CTPS, EclipseTM (Varian Medical Systems, Palo Alto, CA, USA), respectively. The plans were designed to deliver prescription doses to internal target volumes (ITV) drawn by a physician on averaged four‐dimensional computed tomography (4D‐CT). Solo plans were imported back to CTPS, and recalculated in CTPS for fair comparison. Both plans were further verified for each patient by recalculating doses in the inhalation and exhalation phases to ensure that all plans met clinical requirements. Plan robustness was quantified on all phases using dose‐volume‐histograms (DVH) indices in the worst‐case scenario. The interplay effect was evaluated for every plan using an in‐house developed software, which randomized starting phases of each field per fraction and accumulated dose in the exhalation phase based on the patient's breathing motion pattern and the proton spot delivery in a time‐dependent fashion. DVH indices were compared using Wilcoxon rank‐sum test.ResultsCompared to the plans generated using CTPS on the averaged CT, Solo plans had significantly better target dose coverage and homogeneity (normalized by the prescription dose) in the worst‐case scenario [ITV D95%: 98.04% vs 96.28%, Solo vs CTPS, P = 0.020; ITV D5%–D95%: 7.20% vs 9.03%, P = 0.049] while all DVH indices were comparable in the nominal scenario. On the inhalation phase, Solo plans had better target dose coverage and cord Dmax in the nominal scenario [ITV D95%: 99.36% vs 98.45%, Solo vs CTPS, P = 0.014; cord Dmax: 20.07 vs 23.71 Gy(RBE), P = 0.027] with better target coverage and cord Dmax in the worst‐case scenario [ITV D95%: 97.89% vs 96.47%, Solo vs CTPS, P = 0.037; cord Dmax: 24.57 vs 28.14 Gy(RBE), P = 0.037]. On the exhalation phase, similar phenomena were observed in the nominal scenario [ITV D95%: 99.63% vs 98.87%, Solo vs CTPS, P = 0.037; cord Dmax: 19.67 vs 23.66 Gy(RBE), P = 0.039] and in the worst‐case scenario [ITV D95%: 98.20% vs 96.74%, Solo vs CTPS, P = 0.027; cord Dmax: 23.47 vs 27.93 Gy(RBE), P = 0.027]. In terms of interplay effect, plans generated by Solo had significantly better target dose coverage and homogeneity, less hot spots, and lower esophageal Dmean, and cord Dmax [ITV D95%: 101.81% vs 98.68%, Solo vs CTPS, P = 0.002; ITV D5%–D95%: 2.94% vs 7.51%, P = 0.002; cord Dmax: 18.87 vs 22.29 Gy(RBE), P = 0.014].ConclusionsSolo‐generated IMPT plans provide improved cord sparing, better target robustness in all considered phases, and reduced interplay effect compared with CTPS. Consequently, the approximation methods currently used in commercial TPS programs may have space for improvement in generating optimal IMPT plans for patient cases with locally advanced lung cancer.
The Search for Optimal Stereotactic Body Radiotherapy Dose in Inoperable, Centrally Located Non–Small-Cell Lung Cancer Continues
Abstract Background Guidelines to provide recommendations about driving restrictions for patients with brain metastases are lacking. We aim to determine whether clinical neurologic examination is sufficient to predict suitability to drive in these patients by comparison with an occupational therapy driving assessment (OTDA). Methods We prospectively evaluated the concordance between neurology assessment of suitability to drive (pass/fail) and OTDA in 41 individuals with brain metastases. Neuro-oncology evaluation included an interview and neurological examination. Participants subsequently underwent OTDA during which a battery of objective measures of visual, cognitive, and motor skills related to driving was administered. Results The mean age of patients who failed OTDA was age 68.9 years vs 59.3 years in the group members who passed (P = .0046). The sensitivity of the neurology assessment to predict driving fitness compared with OTDA was 16.1% and the specificity 90%. The 31 patients who failed OTDA were more likely to fail Vision Coach, Montreal Cognitive Assessment, and Trail Making B tests. Conclusions There was poor association between the assessment of suitability to drive by neurologists and the outcome of the OTDA in patients with brain metastases. Subtle deficits that may impair the ability to drive safely may not be evident on neurologic examination. The positive predictive value was high to predict OTDA failure. Age could be a factor affecting OTDA performance. The results raise questions about the choice of assessments in making recommendations about driving fitness in people with brain metastases. OTDA should be strongly considered in patients with brain metastases who wish to continue driving.