Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Input: Consider Input: Context: To investigate a putative increased risk of rectal cancer subsequent to prostatic radiotherapy.', 'In an analysis of the Surveillance, Epidemiology, and End Results registry, we compared men who had radiotherapy for prostatic carcinoma with those treated surgically and those treated with neither modality. Kaplan-Meier analyses for the time to failure from rectal cancer were performed between age-matched subgroups of the three cohorts. Cox proportional hazards analyses were performed to ascertain what influences might affect the incidence of subsequent rectal cancer.', 'In all, 33,831 men were irradiated, 167,607 were treated surgically, and 36,335 received neither modality. Rectal cancers developed in 243 (0.7%) of those irradiated (mean age, 70.7 years), 578 (0.3%) of those treated surgically (68.7 years), and 227 (0.8%) of those treated with neither modality (74.2 years). When age effects and the differences between the surgical and untreated cohorts were controlled for, we were unable to demonstrate any significant increased incidence of rectal cancer in men irradiated for prostatic cancer.
Answer: An increased frequency of rectal cancer after prostatic irradiation, apparent on crude analysis, could be attributed to age confounding and other unmeasured confounders associated with prostate cancer treatment and rectal cancer risk.

Output: Is prostatic irradiation associated with any measurable increase in the risk of subsequent rectal cancer?

Input: Consider Input: Context: Women have poorer outcomes after vascular surgery as compared to men as shown by studies recently. Frailty is also an independent risk factor for postoperative morbidity and mortality. This study examines the interplay of gender and frailty on outcomes after infrainguinal vascular procedures.', 'The American College of Surgeons National Surgical Quality Improvement Program database was used to identify all patients who underwent infrainguinal vascular procedures from 2005-2012. Frailty was measured using a modified frailty index (mFI; derived from the Canadian Study of Health and Aging). Univariate and multivariate analysis were performed to investigate the association of preoperative frailty and gender, on postoperative outcomes.', 'Of 24,645 patients (92% open, 8% endovascular), there were 533 deaths (2.2%) and 6198 (25.1%) major complications within 30 d postoperatively. Women were more frail (mean mFI = 0.269) than men (mean mFI = 0.259; P < 0.001). Women and frail patients (mFI>0.25) were more likely to have a major morbidity (P < 0.001) or mortality (P < 0.001) with the highest risk in frail women. On multivariate logistic regression analysis, female gender and increasing mFI were independently significantly associated with mortality (P < 0.05) as well as major complications. The interaction of gender and frailty in multivariate analysis showed the highest adjusted 30-d mortality and morbidity in frail females at 2.8% and 30.1%, respectively and that was significantly higher (P < 0.001) than nonfrail males, nonfrail females and frail males.
Answer: Female gender and frailty are both associated with increased risk of complications and death following infrainguinal vascular procedures with the highest risk in frail females. Further studies are needed to explore the mechanisms of interaction of gender and frailty and its effect on long-term outcomes for peripheral vascular disease.

Output: Do gender and frailty predict poor outcomes in infrainguinal vascular surgery?

Input: Consider Input: Context: We aimed to develop a hippocampal vascular injury surrogate marker for early prediction of late neurocognitive dysfunction in patients receiving brain radiation therapy (RT).', 'Twenty-seven patients (17 males and 10 females, 31-80 years of age) were enrolled in an institutional review board-approved prospective longitudinal study. Patients received diagnoses of low-grade glioma or benign tumor and were treated by (3D) conformal or intensity-modulated RT with a median dose of 54 Gy (50.4-59.4 Gy in 1.8-Gy fractions). Six dynamic-contrast enhanced MRI scans were performed from pre-RT to 18-month post-RT, and quantified for vascular parameters related to blood-brain barrier permeability, K(trans), and the fraction of blood plasma volume, Vp. The temporal changes in the means of hippocampal transfer constant K(trans) and Vp after starting RT were modeled by integrating the dose effects with age, sex, hippocampal laterality, and presence of tumor or edema near a hippocampus. Finally, the early vascular dose response in hippocampi was correlated with neurocognitive dysfunction at 6 and 18 months post-RT.', 'The mean K(trans) Increased significantly from pre-RT to 1-month post-RT (P<.0004), which significantly depended on sex (P<.0007) and age (P<.00004), with the dose response more pronounced in older females. Also, the vascular dose response in the left hippocampus of females correlated significantly with changes in memory function at 6 (r=-0.95, P<.0006) and 18-months (r=-0.88, P<.02) post-RT.
Answer: The early hippocampal vascular dose response could be a predictor of late neurocognitive dysfunction. A personalized hippocampus sparing strategy may be considered in the future.
Output: Does a Radiation-Induced Hippocampal Vascular Injury Surrogate Marker predict Late Neurocognitive Dysfunction?