Stereotactic Radiosurgery   

In light of the recent consensus contouring guidelines (Soliman et al., IJROBP 2017): 1) Are you routinely expanding along the dura up to 5-10 mm...

With the recent publication in IJROBP showing a greater than 50% response rate, have you started integrating this into your practice? 

Can this be done right away or do you wait for the cavity to involute before you plan postop SRS to cavity?

This has become standard practice at our institution for patients with a good performance status, with whole brain radiotherapy given after the comple...

If so - how long?

Does fractionation (or location) influence this decision? What is your preferred steroid dose?

In patients with contraindications to receiving an MRI scan, are other imaging modalities sufficient to treat patients with SRS?

Is there a certain amount of time that you prefer to have elapsed after the last infusion before delivering SRS? Do you avoid all subsequent Trastuzum...

Do you have a number/volume threshold for SRS vs WBRT?

If imaging is aligned at PTV despite exceeding tolerances do you accept/override, perform shift verification image, or reposition the patient? Do you...

Based on recent ASTRO data, what is your selection criteria and size cutoffs?

I have seen small amounts of evidence for V4<20cc and V14<7cc, but overall it seems like there is little published on this issue.  

Do you treat on consecutive days or more protracted interfraction intervals? Does tumor type (benign vs malignant) or size influence your choice?

Should it include the entire brain (normal brain + target) or just the normal brain (brain - target)?  How does the V10 or V12 constraint change ...

What maximum dose do you allow to “connect” adjacent metastatic lesions receiving SRS/SRT? What is this value for one-, three-, and five-...

Is there evidence that supports/refutes the safety of concurrent use?

Does this affect your subsequent imaging surveillance frequency?

Do you decrease total dose, increase the number of fractions, or both? What factors, in addition to size and location, do you consider?

How does the presence of prior WBRT alter your treatment plan?

If progression is proven by imaging modality (MRI spectroscopy, perfusion and PET/CT), is there evidence for retreatment with a second course of SRS?&...

Would you ever de-escalate your prescription dose in order to reduce cochlear dose when treating younger patients with intact hearing?

Do you ever boost the areas of residual tumor or do you treat the cavity and tumor as a homogeneous target volume?

Given the proximity of the optic chasm and risk of compromised hemianopsia, the lack of adequate central vision adds another layer of risk.

When do you decrease your SRS dose or consider fractionated SRS regimens?

With the publication of the ARUBA trail results, should management of AVMs shift toward medical management?  

What constraints do you use for plan evaluation?

If so, how long should the medication be stopped prior to SRS?

Will this disappear over time on its own or should I be concerned that the necrosis will worsen over time, and repeat MRI more frequently?

Do you utilize fMRI or other advanced sequences (DTI, etc) in the planning process?  

How do these change in the setting of previous radiotherapy/radiosurgery?

When do you decide to fractionate?

What dose/fractionation do you prefer for small vs large metastases?

How should they be prioritized? V10, V12, mean brain dose, prior WB radiation? To what extent should tumor coverage, conformality and homogeneity be c...

Do you fractionate? Do you look at composite doses and/or apply any constraints given the limited data?

Can a second course of SRS be completed? If so, what dose do you recommend?

Is SRS reasonable if there is no evidence of more diffuse disease?

How do you sequence imaging and headframe placement? Do you fuse a 3D CTA to the planning CT?

There are data for improved outcomes for inhomogeneous dose distribution in patients with intact brain tumors (Lucia et al, Radiother Oncol 2018), but...

Is there an optimal time to give SRS to brain metastases for patients receiving ipilimumab and nivolumab?

Do you modify your dose/fractionation if the target volume abuts surgically implanted hardware?

If so, what constraint is most clinically relevant? The EORTC LungTech trial (60Gy/8 fractions) does not specify a chest wall constraint. I have...

It becomes challenging to keep track of different metastases, especially for patients who have undergone one or more prior SRS treatments.

Would this be any different for whole brain radiotherapy?

Would you offer 3-5 fractions for larger lesions instead or would you favor more traditional standard fractionation regimens?

Do you routinely pause systemic therapy when administering SRS? Which agents do you view as relative or absolute contraindications with SRS?

Do you make any modifications to your treatment field or dose?

In our clinical experience, we have used the treatment planning system's auto-match method, and then manually fine tune adjustments checking skull, IA...

The small series by Lowell et al (IJROBP 2011) suggests significant toxicity risks following SRS.

What is your cavity size/volume cutoff in selecting hypofractionated SRT over SRS?

For treatment of multiple brain metastases, the V12 can often exceed the traditional dose constraint of 10 cc, especially as the number of lesions bei...

Are there treatment planning considerations that are different for a large cystic lesion as compared to a solid metastasis?

If you do treat both nerve roots, how long do you wait between fractions?  Do you modify anything because you are treating bilaterally?

There are solid data from Emory, Korea and others suggesting that is as effective as single fraction SRS but has less complications. 

Also, is there a maximum hotspot within the target volume?  

To what degree, if any, is a neurosurgeon involved in the planning of SRS for brain metastases?

The 2014 "Choosing Wisely" list, released this past September, includes the assertion that we should not "routinely add adjuvant whole brain radiation...

And at what intervals? The published trials/RTOG call for q3 month MRI follow-up. Is this appropriate outside a clinical trial setting? 

One study comparing these techniques (https://www.ncbi.nlm.nih.gov/pubmed/12873685) showed 75% hearing preservation in the single fraction group ...

If there was true residual disease, do you offer whole brain RT, partial brain RT, SRS boost to the resection cavity, or observation?

For example, in a patient minimal brain and liver metastasis, would you treat all sites definitively?

There are retrospective data (i.e. PMID 15072456) that seem to associate posterior fossa location with increased risk of leptomeningeal disease a...

For instance, in a patient with Her2(+) breast cancer and 3x small newly diagnosed asymptomatic brain metastases, would you consider a trial of TDM-1 ...

How much do you factor in the possibility of radiation-induced second malignancies for the treatment of benign conditions in younger patients?

Do you adjust your dose based on previous whole brain radiation? What time interval would you wait following whole brain or would you treat with upfro...

In keeping with prior randomized trials, Alliance N0574 demonstrated that SRS+WBRT provides superior intracranial disease control but w...

A recent gamma knife retrospective study from Cleveland Clinic (Mohammadi et al., PMID 27231978) argues for the RTOG dose of 24 Gy, although the ...

Assuming other variables, such as number/volume of brain lesions, KPS, and extra-cranial disease status are equal, would HER2 status in a breast cance...

If so, what dose should be used? 

Any advice on how to safely incorporate it into our practice?

How do the number of lesions treated and histology affect your decision making?

While the Duke randomized study found similar rates of control with 1mm v. 3mm margins and higher radionecrosis with 3mm, it did not look at treating ...

Is heparin or warfarin routinely held prior to treatment?  

In RTOG 9508, 4 cm was the cut-off size for WBRT followed by SRS. 

The retrospective series quote a local control rate of 85-90% at one year and the current NCCN guidelines list this as an option following surgery for...

We are in the process of implementing a BrainLab SRS program for intracranial sites.  In my previous experience, all of the planning and set-up f...

It is my impression that for brain metastases >3 cm it may be preferable to deliver fractionated SRT versus the RTOG dose of 15 Gy SRS, if WBRT is ...

Our neurosurgeons have been pushing for definitive and postop SRS in patients with a poor performance status. Should I consider this or is it tot...