Table 2.

Characteristics of the 12 studies.

Author [reference], country	Study design	Study sample	Intervention methods	Intervention duration	Outcome/instrument	Main results
Feyzioğlu et al [22], Turkey	RCTa	Forty women with breast cancer were randomly assigned to the experimental group (use of Xbox 360 Kinect–based VRb training) and the control group (standardized physical therapy group).	Xbox 360 Kinect–based VR training: using Kinect Sports I (darts, bowling, boxing, beach volleyball, table tennis) and Fruit Ninja.	A total of 6 weeks of exercising with the Kinect (duration of 35 minutes/day for 2 days per week).	VASc, ROMd, arm strength, DASHe questionnaire, TKSf	Significant changes in pain, ROM, muscle strength, grip strength, functionality, and TKS scores after the treatment (P<.05).
Chirico et al [14], Italy	Externally controlled trial	Patients were randomly assigned to the VR or music group (MT) and were compared with a nonconcurrently recruited control group. Thirty patients were included in the VR intervention group, 30 patients in the MT intervention group, and 34 patients constituted the control group.	Vuzix Wrap 1200VR head-mounted glasses with the Second Life platform was used to explore an island, walk through a forest, observe different animals, climb a mountain, and swim in the sea.	Patients used the equipment for 20 minutes during chemotherapy.	SAIg, SV-POMSh, VRSQi	VR and MT are useful interventions for alleviating anxiety and for improving mood states in patients with breast cancer during chemotherapy (P<.05). VR seems more effective than MT in relieving anxiety, depression, and fatigue.
Atef et al [39], Egypt	Quasi-randomized clinical trial	Fifteen participants were assigned to the experimental group (use of Nintendo Wii) and 15 to the control group (proprioceptive neuromuscular facilitation).	Nintendo Wii game: tennis, triceps extension, and rhythmic boxing.	The duration of the VR-based therapy sessions included 30 minutes of training over a period of 4 weeks, with 2 sessions every week.	Circumferential measurements, excess arm volume, QuickDASH-9 scale	VR is beneficial in reducing postmastectomy lymphedema (P<.05) and can be used as an exercise-based technique in those who have undergone modified radical mastectomy with axillary lymph node dissection as it motivates and provides visual feedback to patients.
Buche et al [17], France	Pre–posttest	In a physiotherapy center, each of the 46 patients participated in 4 experimental conditions in a random order: 2 sessions used virtual immersion (ie, 1 participatory and 1 contemplative), 1 session proposed musical listening, and the fourth was a standard session care.	The Greener Gamer’s Nature Treks VR relaxation application has 9 relaxing visual environments with relaxing sounds, including 2 immersive modes: contemplative mode and participatory mode.	The sessions were performed over a period of 10 months in a physiotherapy center. Each session lasted an average 30 minutes.	ITC–SOPIj, feeling of elapsed time, SAI, QCk	An increase in positive emotions (ie, joy and happiness) and a decrease in anxiety regardless of which support methods were offered (P<.05). Participatory VR created a more intense feeling of spatial presence.
Jimenez et al [40], Australia	Quasi-experimental design study	Patients with breast cancer (n=18) in the control group received the standard pre-RTl education package at a targeted cancer therapy center. Patients with breast cancer (n=19) in the experimental group attended a VERTm-based education session detailing RT immobilization, planning, and treatment.	The VERT education program incorporated low-level technical information about RT, patient anatomy, and radiation dose. Aspects of immobilization, simulation, planning, and treatment pertinent to patients with breast cancer were explored.	Each patient attended 1 session, with each session lasting 1 hour.	Radiation therapy knowledge and experience, STAIn	VERT breast cancer–targeted education programs are of high value, which can improve patients’ RT knowledge (P<.05) and decrease their anxiety (P>.05).
Bani et al [16], Jordan	RCT	Female patients with breast cancer (n=80) were randomly assigned to the intervention and comparison groups.	The intervention group chose 2 scenarios: deep sea diving “Ocean Rift” or sitting on the beach with the “Happy Place” track.	The VR exposure session was ended at the peak time of painkiller efficacy.	VAS, SAI, MMSEo	One session of immersive VR plus morphine resulted in a significant reduction in pain and anxiety self-reported scores, compared with morphine alone, in patients with breast cancer (P<.05).
House et al [30], USA	Pre–posttest	Community-dwelling women (n=6) with postsurgical breast cancer pain in the upper arm.	The BrightArm Duo Rehabilitation System consists of a low-friction robotic rehabilitation table, computerized forearm supports, a display, a laptop for the therapist station, a remote clinical server, and a library of custom integrative rehabilitation games.	The duration of the VR-based therapy sessions progressed from 20 to 50 minutes, twice a week for 8 weeks.	BDI-IIp, BVMT-Rq, TMT-Ar, TMT-Bs, NABt, NPRSu, HVLT-Rv, and PHQ-9w	Pain intensity showed a 20% downward trend. Outcomes indicate improvement in cognition, shoulder range, strength, function, and depression.
Schneider et al [15], USA	RCT: crossover design	A crossover design was used to examine the effects of a VR distraction intervention on chemotherapy-related symptom distress levels in 16 women aged ≥50 years.	Participants chose from 3 CD-ROM–based scenarios: Oceans Below, A World of Art, or Titanic: Adventure Out of Time.	Participants wore the head-mounted device during their intravenous chemotherapy treatment. Each scenario could last up to several hours.	MMSE, PFSx, SAI, SDSy	A significant decrease in the SAI (P=.10) scores was observed immediately following chemotherapy treatments when participants used VR. No significant changes were found in SDS or PFS values. There was a consistent trend toward improved symptoms on all measures 48 hours following completion of chemotherapy.
Schneider et al [41], USA	RCT: crossover design	A crossover design was used to examine the effects of a VR distraction intervention on chemotherapy-related symptom distress levels in 20 women aged 18-55 years.	Participants chose from 3 CD-ROM–based scenarios: deep sea diving, walking through an art museum, or solving a mystery.	During the chemotherapy infusions, participants received the VR distraction intervention for 45-90 minutes.	SDS, STAI, PFS, evaluation of VR intervention	The major findings of this study demonstrated that symptom distress and fatigue were significantly lower following chemotherapy treatment during which the VR intervention was implemented.
Jin et al [42], China	RCT	Patients with breast cancer (n=38) assigned to the experience group received VR-based training, and the other 38 patients with breast cancer in the control group received standard physical training.	A rehabilitation VR system including a video learning module, an action acquisition module, and an action scoring module.	A total of 3 months, 15–30 minutes per session, twice per day.	Adherence, ROM, the climbing height of finger, degree of edema.	The VR system with auxiliary game treatment was able to substantially improve limb function recovery, compliance, and subjective initiative in rehabilitation training, and reduce the edema of affected limbs (P<.05).
Zhu et al [43], China	RCT	Patients with breast cancer (n=80) who were randomly assigned to the experience group received VR-based training, while the control group received standard physical training.	Patients received VR-based shoulder and hand rehabilitation exercises.	A total of 3 months, 15–30 minutes per session, twice per day.	Adherence, ROM, the climbing height of finger, incidence of lymphedema	The VR rehabilitation system improved limb function recovery, compliance, and reduced the incidence of lymphedema (P<.05).
Chen et al [44], China	Pre–posttest	Patients with breast cancer (n=80) with cognitive impairment after chemotherapy.	The 80 patients received virtual cognitive intervention training.	An 8-week intervention	MoCAz, activities of daily living	The scores of the Montreal Cognitive Assessment Scale increased significantly and the scores of ADL were lower than those before the intervention (P<.05).

^aRCT: randomized controlled trial.

^bVR: virtual reality.

^cVAS: visual analog scale.

^dROM: range of motion.

^eDASH: disability of the arm, shoulder, and hand.

^fTKS: Tampa Scale of Kinesiophobia.

^gSAI: State Anxiety Inventory.

^hSV-POMS: short version of Profile of Mood States.

ⁱVRSQ: Virtual Reality Symptom Questionnaire.

^jITC–SOPI: Independent Television Commission–Sense of Presence Inventory.

^kQC: a questionnaire on cybersickness.

^lRT: radiation therapy.

^mVERT: Virtual Environment for Radiotherapy Training.

ⁿSTAI: State-Trait Anxiety Inventory.

^oMMSE: Mini-Mental State Examination.

^pBDI-II: Beck Depression Inventory, Second Edition.

^qBVMT-R: Brief Visuospatial Memory Test, Revised.

^rTMT-A: Trail Making Test A.

^sTMT-B: Trail Making Test B.

^tNAB: Neuropsychological Assessment Battery.

^uNPRS: Numeric Pain Rating Scale.

^vHVLT-R: Hopkins Verbal Learning Test, Revised.

^wPHQ-9: Patient Health Questionnaire.

^xPFS: Piper Fatigue Scale.

^ySDS: Symptom Distress Scale.

^zMoCA: Montreal Cognitive Assessment.